The present invention relates to a movable scaffold for constructions, and more particularly to a movable scaffold used for maintenance such as repairs and painting of walls of a construction such as a bridge.
Usually, for maintenance work, a scaffold is assembled on the ground by steel pipes or a crane truck with a lifter is employed. Further, for maintenance work for big constructions such as a bridge, overhead road, and a gymnasium, the scaffold is mounted on beams of the construction so as to move along the beams, for continuously performing the maintenance work. Japanese Patent No. 1222171 discloses such a movable scaffold.
Since the maintenance work is performed, moving the scaffold along the beams, the width of the scaffold is set to a predetermined value corresponding to the distance between beams. However, at the exit or entrance zone of the highway, for example, the width of the road and hence the distance between the beams changes. Accordingly such a scaffold cannot be used with such a construction in which the distance between beams changes. Further, as shown in FIG. 7, when a beam 3a is obliquely mounted on a pier 5 in a plan view, the scaffold 8 cannot be moved to an end porion of the beam, so that the maintenance work cannot be performed at a section S indicated by a checkered pattern.